Commit 257dc723 authored Dec 22, 2020 by Philipp Tomsich Committed by Chen Jun Jan 07, 2021

arm64:ilp32: add vdso-ilp32 and use for signal return

maillist inclusion
category: feature
bugzilla: 46790
CVE: NA

Reference: https://github.com/norov/linux/commits/ilp32-5.2



--------------------------------

ILP32 VDSO exports following symbols:
 __kernel_rt_sigreturn;
 __kernel_gettimeofday;
 __kernel_clock_gettime;
 __kernel_clock_getres.

What shared object to use, kernel selects depending on result of
is_ilp32_compat_task() in arch/arm64/kernel/vdso.c, so it substitutes
correct pages and spec.

Adjusted to move the data page before code pages in sync with
commit 601255ae ("arm64: vdso: move data page before code pages")

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Signed-off-by: Christoph Muellner <christoph.muellner@theobroma-systems.com>
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Signed-off-by: Bamvor Jian Zhang <bamv2005@gmail.com>
Signed-off-by: Yury Norov <ynorov@marvell.com>

 Conflicts:
	arch/arm64/Makefile
	arch/arm64/kernel/Makefile
	arch/arm64/kernel/asm-offsets.c
	arch/arm64/kernel/vdso.c
	arch/arm64/kernel/vdso/gettimeofday.S
[wangxiongfeng: rewrite vdso-ilp32/Makefile according to vdso/Makefile]
Signed-off-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Acked-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Chen Jun <chenjun102@huawei.com>

parent 7d74a927

arch/arm64/Makefile

+3 −0

Original line number	Diff line number	Diff line
		@@ -183,6 +183,9 @@ vdso_prepare: prepare0
		$(if $(CONFIG_COMPAT_VDSO),$(Q)$(MAKE) \
		$(build)=arch/arm64/kernel/vdso32 \
		include/generated/vdso32-offsets.h)
		ifeq ($(CONFIG_ARM64_ILP32), y)
		$(Q)$(MAKE) $(build)=arch/arm64/kernel/vdso-ilp32 include/generated/vdso-ilp32-offsets.h
		endif
		endif

		define archhelp

arch/arm64/include/asm/vdso.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -21,6 +21,12 @@
		#include <generated/vdso32-offsets.h>
		#endif

		#ifdef CONFIG_ARM64_ILP32
		#include <generated/vdso-ilp32-offsets.h>
		#else
		#define vdso_offset_sigtramp_ilp32 ({ BUILD_BUG(); 0; })
		#endif

		#define VDSO_SYMBOL(base, name) \
		({ \
		(void *)(vdso_offset_##name - VDSO_LBASE + (unsigned long)(base)); \

arch/arm64/kernel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -66,6 +66,7 @@ obj-$(CONFIG_ARM64_MTE) += mte.o

		obj-y += vdso/ probes/
		obj-$(CONFIG_COMPAT_VDSO) += vdso32/
		obj-$(CONFIG_ARM64_ILP32) += vdso-ilp32/
		head-y := head.o
		extra-y += $(head-y) vmlinux.lds

arch/arm64/kernel/asm-offsets.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -94,6 +94,13 @@ int main(void)
		BLANK();
		DEFINE(PREEMPT_DISABLE_OFFSET, PREEMPT_DISABLE_OFFSET);
		BLANK();
		#ifdef CONFIG_COMPAT
		DEFINE(COMPAT_TVAL_TV_SEC, offsetof(struct old_timeval32, tv_sec));
		DEFINE(COMPAT_TVAL_TV_USEC, offsetof(struct old_timeval32, tv_usec));
		DEFINE(COMPAT_TSPEC_TV_SEC, offsetof(struct old_timespec32, tv_sec));
		DEFINE(COMPAT_TSPEC_TV_NSEC, offsetof(struct old_timespec32, tv_nsec));
		BLANK();
		#endif
		DEFINE(CPU_BOOT_STACK, offsetof(struct secondary_data, stack));
		DEFINE(CPU_BOOT_TASK, offsetof(struct secondary_data, task));
		BLANK();

arch/arm64/kernel/vdso-ilp32/.gitignore

0 → 100644

+2 −0

Original line number	Diff line number	Diff line
		vdso-ilp32.lds
		vdso-ilp32-offsets.h